Escapement mechanism



1949- R. M. FLANAGAN 60,000

E S CAPEMENT MECHANISM I Original Filed Jan. 9, 1945 2 Shgets-Sheet l INVENTOR 12 1 1 7 3 HUBEM m. FL fiNfiEfi/V ATTORNEY Jan. 25, 1949. R. M. FLANAGAN 2,400,000

ESCAPEMENT MECHANISM Original Filed Jan. 9, 1945- 2 Sheets-Sheet 2 35 ff 7 34 V o INVENTOR HUBER? 772. FLHNWEHN ATTORN Patented Jan. 25, 1949 ESCAPEMENT MECHANISM Robert Michael Flanagan, Morris Plains, N. J assignor to Bendix Aviation Corporation, Teterboro, N. 5., a corporation of Delaware Original application January 9, 1945, Serial No.

572,017. Divided and this application December 23, 1946, Serial No. 717,838

2 Claims. 1

The present application is a division of my copending application Ser. No. 572,017, filed January 9, 1945, and relates to a novel escapement mechanism.

More particularly the present invention relates to a novel snap action escapement mechanism for controlling the operation of a mechanism such as an air distributor valve for inflatable ice eliminating boots or elements.

An object of the invention is to provide a snap action escapement mechanism having a novel compact assemblage.

Another object of the invention is to provide a novel spring wound snap action mechanism, including safety means so arranged that in the event of breakage of the actuating spring a continued driving relation ma be effected,

Another object of the invention is to provide a novel snap action mechanism including driving and driven members, together with cam means on the driving member for terminating operation of a driving motor at a predetermined position of the driving member.

These and other objects and features of the invention are pointed out in the following description in terms of the embodiments thereof which are shown in the accompanying drawings. It is to be understood, however, that the drawings are for the purpose of illustration only, and are not designed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

Figure l is an exploded perspective view of the snap action spring actuating mechanism.

Figure 2 is an end view of the mechanism of Figure l and showing the same in operating relation.

Figure 3 is a side view of Figure 2.

Figure 4 is an end View of a device embodying the invention and showing a fragmentary sectional View of the snap action mechanism with certain parts .broken away to better illustrate the same.

Figure 5 is a diagrammatic view of the energizing circuit for the driving motor of the mechanism and illustrating the operation of the limit switch.

Referring to the drawing of Figure 4, there is provided a main casting or housing l which carries a suitable electric motor indicated dia" grammatically in Figure 5 by the numeral 2. The motor 2 drives through suitable means described in detail in the copending patent application Ser. No. 572,017 operating mechanism for inflatable ice eliminating elements. The

latter operating mechanism includes a pump 3 and a shaft 4 drivingly connected to the motor 2. The shaft 4 is rotatably mounted in suitable bearing members carried by the housing l. The shaft 4 has a suitable helical or worm gear 5 which in Figure 4 is shown broken away so as to better illustrate the invention.

Operably connected to the worm gear 5 is a gear 6 which is connected to a novel snap action spring actuated escapement mechanism indicated generally by the numeral 1. The latter mechanism effects actuation of a shaft 8 with a snap action so as to adjustably position a rotaryvalve connected thereto and forming part of a valve mechanism 9. The valve mechanism 9 may be of a type such as shown and described in the copending parent application Ser. No. 572,017 filed January 9, 1945.

The snap action operation of the rotary valve is effected through the operation of the novel escapement mechanism 1 shown in Figure 4 and in detail in Figures 1, 2 and 3.

The escapement mechanism 1 is driven by shaft 4 and gears 5 and 6 from the electric motor 2 as previously described. The gear 6 is freely mounted on the shaft 8 and has afiiXed thereto a cup shaped member ID having an end plate II. The member It has formed around the cir cumferential edge thereof radially projecting escapement cam teeth [2.

As shown in Figure 1, the shaft 8 projects through the cup shaped member l0 and has formed thereon a cam member I3. Radially projecting from the cam member l3 are cam teeth l4 formed around the circumferential edge of the member l3. The cam teeth l4 cooperate with the cam teeth l2 as will be explained hereinafter.

Eccentrically positioned Within the cup shaped member I0 and projecting axiall from the end plate II is a pin I5. This pin I5 is arranged to project through a looped end 16 of a spiral spring I! positioned within the cup shaped member in and about the shaft 8. The opposite end It of the spring ll is fastened by a pin l9 to the cam A cam slot 20 is formed in the cam 13 and there is disposed in the slot 20 the pin I5. The cam teeth l2 have provided cam surfaces 2| which, as shown in Figures 1 and 2, rise in a counterclockwise direction from the inner end of the preceding cam tooth l2 to the outer end of the succeeding tooth I 2.

The cam teeth [4 have similarly provided cam surfaces 22 which rise in a clockwise direction tion under tension of thespring ll.

from the inner end of the preceding cam tooth Hi to the outer end of the succeeding tooth I 4.

The teeth [2- and I4 carried by the members H and i3, respectively are positioned, circumferentially in spaced relation so that a pawl 23 may be biased under force of a spring 2 so as to fall successively into the interdental spaces between the teeth !2 and M, as shown in Figure 2. The pawl 23 is slidably mounted in a suitable means provided in the casting i end of the pawl 23 rides along the cam surface 2i as the member H! is rotated in a clockwise direction, as viewed in Figure 1, causing the pawl 23 to move out radially from the shaft 8. Since the pawl locks the tooth It from movement, such rotary movement of the driving member iii winds up or tightens the spring l6 fastened to the members Iii and 13 through the pins 15 and I9 respectively.

The pawl 23 thus moves out radially from the driven shaft 8 and the pin moves in the slot 26in a clockwise direction until a point is reached where the pawl .23 is raised by the cam surface 2! above the surface of the engaging tooth l4. At the latter point the pawl 23' permits the tooth is to move with a snap action in a clockwise direc- The movement of the member l3 under tension of the spring ii is limited by the pin in the slot 28.

Further rotary movement of'the cam members it then positions the next succeeding tooth I2 so that the pawl 23 is moved under'force of the spring I? into the interdental space between the next succeeding teeth l2 and M, respectively.

Such snap action movement of the cam member :3 causes a corresponding snap action rotary movement to the driven shaft 8, which in turn imparts a snap action movement to the rotary valve of the mechanism 9, adjusting the same into the next succeeding position, as'previously explained.

As shown in Figure 4, the lower end of the driven shaft 8 rotates in a bearing member 24 carried by a plate 25 secured to the casting I by bolts 28. The latter end of the shaft 8 rotates upon a positioning screw 2?. A removable cap 28 is screw threadedly mounted on the plate 25 and covers the screw 21.

As shown in Figures 3 and 4, there is mounted on the end plate 1 l at the outer side thereof a cam surface 29 which at a given position of the driving member H3. actuates a pin 39 operably connected to a lever 3| pivoted'at 32 and'arranged so as to actuate through a'button 33, a switch 36.

The detail structure of the switch 34 is not shown, but the same ispreferably of a snap acting normally closed type, well'known in the art. Thus upon inward actuation of the button 33 upon a predetermined movement of the pin the switch 34 is opened. The switch 34, as shown in Figure 5, is connected by conductors 35 and 36 in shunt relation to a main control switch 31. The switch 3! is connected in an electrical conductor et'leading from one terminal of a source of electrical "energy 39 to an'input terminal of the electric motor 2. Another electrical conductor :26 leads from the'opposite terminal of the source of electrical energy 39 to the other inputrterminal f the motor 2.

The switch 34 is so arranged that if the main control switch S'l'be opened, the circuit to the motor 2 will be held-closed until the driving member iii reaches a predetermined position at Which the cam 29 opens switch 34. Thus upon The inner the opening of the main control switch 31, the motor 2 will continue to run until the distributor valve returns to its home position at which switch 3 opens.

t will be readily seen from the foregoing that there has been provided novel compact mechanism in which there is, provided a motor 2 which drives an inflating pump 3 and a snap action timing mechanism 7 for operating an air distributor valve mechanism 9 for controlling the inflation and deflation of suitable inflatable elements for removing ice from airfoil surfaces of an aircraft.

Further, there is provided a safety means whereby in the event the actuating spring I! should break the distributor valve in mechanism 9 will continue to be rotated through the action of pin 55 of the driving member I l which engages in the slot 20 of the driven member l3 so that there is a direct drive between the motor and the distributor in such emergency.

These and other objects and features of the invention are pointed out in the following description in' terms of the embodiment thereof which is shown in the accompanying drawings. It is to be understood, however, that the drawings are for the purpose of illustration only, and are not designed as a" definition of the limits of the invention, reference being had to the appended claims for this purpose.

What is claimed is:

1. The combination, comprising, a first element, a second element, spring means drivingly connecting said first and second elements, power means for driving said first element, means for controlling said power means, a releasable holding means normally positioned so as to hold said second element from movement, cam means carried by said first-element for urging said holding meansin a predetermined direction for releasing said second element under tension of said spring means, engaging means carried by one of said elements for limiting the relative movement between said elements under tension of said spring, actuating means carried by one of said elements, said control'm'eans afiected by said actuating means for terminating operation of said power means at a predetermined position of said first element, and said engaging means efiecting a direct driving connection between said first and second elements upon breakage ofthe spring means and until termination of operationof said power means by said actuating means.

2. An escapement mechanism comprising, a first rotatable'toothed member, asecond rotatable toothed member, a shaft; said first member freely mounted on said shaft and said second member affixed to saidshaft, oneof said members being of a cup shape and the other of said members positioned at the open end of said cup shaped member, a spiral spring positioned within said.

cup shapedmember and about said shaft, said spring drivingly connecting said first and second members, electric motor means for driving one of said'members 'tliroughthe' other member, the, teeth oithe first, of said toothed members positioned in spaced relation to the teeth of the secondof saidtoothed members, a pawl, means biasing onesendfof said pawl into the interdental space between a tooth of the first too thed member I and at'ooth of the second toothed member for holding'one of said'toothed members from rotation relative to the other of said toothed members, a cam surfacecarried by said other toothed memberfor urging said a circuit for energizing said motor means, switch 10 means for controlling said circuit, and cam means operated by one of said members for opening said switch means and circuit at a predetermined position of said last mentioned member and said pin effecting a direct driving 15 2,073,983

connection between said first and second memhers upon breakage of the spiral spring and until said cam means opens said switch means.

ROBERT MICHAEL FLANAGAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,616,501 Horton Feb. 6, 1912 1,411,712 Diehl Apr. 4, 1922 1,891,101 Le Count Dec. 13, 1932 Anderson Mar. 16, 1937 

